List variants

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It conveys that this is a read-only listing operation and states the output categories, but it does not explicitly mention side-effect-free behavior, authentication needs, or behavior when no variants are installed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One concise sentence front-loads the action and lists exactly what the tool returns. There is no redundancy, filler, or restatement of the title beyond what is useful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a simple, zero-parameter tool, and the description lists the full scope of returned information. The absence of an output schema means the exact response structure is not specified, but the description is sufficient for an agent to decide whether to call it and to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters, so the input schema is trivially complete and there is nothing for the description to add. The description's mention of variants, options, and formats is about output content, not parameter meaning. Baseline 4 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('List') and names the exact resources: installed variants, their options, move schemas, and supported import/export formats. This clearly distinguishes it from the game-action siblings like new_game, play_move, and export_game.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The use case is implied by the content: an agent would call this to discover available variants or formats before creating a game or importing. However, it does not explicitly state when to use it versus alternatives, nor does it provide any when-not-to-use guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.